WHY DO WE EXPERIENCE SEASONS?
- due to tilt of the Earth (23.5°)
- rotation of the Earth around the Sun
- results in sunlight striking the Earth's surface at different angles
EQUATOR
Since the North and South poles are pointed 23.5° away from the Sun, the Sun's light and heat energy strikes the central area of Earth most directly. Therefore, those who live along the equatorial region experience year round tropical weather conditions (hot and windy with occasional rain).
For those who learn with pictures:
For those who learn with words:
WINTER AND SUMMER SOLSTICE
Refer to the above picture and see the Earth's position when it is 21st June and 22nd December. They experience summer solstice and winter solstice respectively.
For 21st June, the North hemisphere tilts towards the Sun while the South hemisphere tilts away. Since the angle that strikes the North hemisphere is a direct angle, the heat energy is more concentrated than that at the South hemisphere. Hence when the North hemisphere experiences summer, the South hemisphere experiences winter and vice versa.
For 22nd December, the South hemisphere tilts towards the Sun. As such it would experience summer, while the North hemisphere would experience winter.
AUTUMNAL AND VERNAL EQUINOX (FALL AND SPRING)
The seasons known as spring and autumn are transitional phases as the sun's rays become refocused. Many events in nature, such as the appearance of new growth in the spring or the shedding of leaves in autumn, are triggered by the changes in temperature or available daylight as the sun's energy becomes more diffused. The changes of season are also an example of nature's law of conservation at work. In Spring and Fall, the days are nearly equal in length for both the Northern and Southern Hemispheres, since the amount of sunlight they receive are nearly equal.
Basically:
MISCONCEPTIONS
1. Seasons are caused by Earth’s distance from the Sun.
When Earth is closer to the Sun, it is warmer and when it is further away, it should colder.
TRUTH: The Earth orbits around the Sun in an elliptical motion (a nearly perfect circle). Therefore, distance from the Earth and Sun cannot be the factor, since the distance is nearly constant. For example when North America experiences summer, South America experiences winter.
2. The tilt of the Earth causes one hemisphere to be closer to the Sun, so the hemisphere that is tilted
toward the Sun will experience summer (true) because it is closer to the
Sun (false). Actually, compared to the Sun, the Earth is so small and far
away that the difference in distance between the hemispheres doesn’t
count for the seasons
TRUTH: The above concept is partially true. The hemisphere tilted towards toward the sun will experience summer. However, the distance from the hemisphere and Sun is not the reason, since there are nearly the same. It is caused by the sunlight striking Earth at different angles due to its tilt.
Resources:
Done by: Jaspreet Kaur
Hey Jas,
ReplyDeleteI would like to ask you on seasons at the equator region, for example Singapore. You have covered on seasons at the more “curved” regions of the earth, meaning away from the earth, where the tilt of the world affects the seasons. However, what about seasons at the equator? Well, I guess we can say that there is no distinct change in the weather but if you look at Singapore, we actually have some sort of a “season” thing, where we have the rainy and sunny season. The weather during December to January is usually the colder and wetter seasons, while during May and June is usually the hotter and drier season. I feel that it is due to monsoon season, which I did a post on but i would like to ask your opinion on how you would account for this phenomenon.
-Li Lin